That’s probably a significantly more difficult problem than stopping pollution as you actually need someone to pay for it directly. And of course we don’t know a good way to only try and cool the Arctic.
<Massive simplifications ahead> You can ballpark this yourself a 288 K black body in equilibrium is radiating as much energy as it receives, at T^4. To drop that by 1C to 287K means blocking 1- ( 287^4 /288^4) or roughly 1.4% of all sunlight. As the earth’s radius 6,371 km ignoring the atmosphere, the classic sunshade at L1 idea needs a surface area of something like 1.7 million km^2. And that’s assuming we didn’t keep dumping any CO2 into the air and ignore the fact the earth isn’t in equilibrium it’s warming etc etc.
A few ideas for getting various things into the upper atmosphere have been considered but reflecting an extra 1.4% or more sunlight would be a true ly Herculean task with any of those ideas and you couldn’t stop as they all decay over time.
<Massive simplifications ahead> You can ballpark this yourself a 288 K black body in equilibrium is radiating as much energy as it receives, at T^4. To drop that by 1C to 287K means blocking 1- ( 287^4 /288^4) or roughly 1.4% of all sunlight. As the earth’s radius 6,371 km ignoring the atmosphere, the classic sunshade at L1 idea needs a surface area of something like 1.7 million km^2. And that’s assuming we didn’t keep dumping any CO2 into the air and ignore the fact the earth isn’t in equilibrium it’s warming etc etc.
A few ideas for getting various things into the upper atmosphere have been considered but reflecting an extra 1.4% or more sunlight would be a true ly Herculean task with any of those ideas and you couldn’t stop as they all decay over time.